The embodiments described herein relate generally to modeled object simulations and, more particularly, to simulations and systems certification.
Generally, cyber-physical systems include both computational and physical elements that are combined and coordinated in operation. One example of a cyber-physical system is an embedded system, such as those used with automobiles (e.g., stability augmentation, ABS systems) and aircraft (e.g., flutter control systems). A characteristic of at least some known cyber-physical systems is that such systems have infinite states.
At least some known simulation systems use fault trees and/or reachability analysis to certify finite state systems, whereby possible system failures are determined by combining one or more known causes and/or faults. However, because fault trees and reachability analysis cannot generally be used with systems of infinite states, these tools are not usable for examining cyber-physical systems.
Other known simulations systems use statistical analysis, such as Monte Carlo simulations, to certify infinite state systems. In such a statistical analysis, calculations of system performance are repeatedly made based on randomly selected values and probability distributions that describe each element of a model. However, some failure events of cyber-physical are so rare that Monte Carlo simulations are not useful for examining these cyber-physical systems because the dataset would be too large. As cyber-physical systems, in the embodiment of embedded systems, become more common and are used in more critical devices, these rare failure modes are becoming more and more important.